Metathesis catalysts

ABSTRACT

The invention relates to polymeric transition metal catalysts, to processes for preparing them, to intermediates and also to the use of the transition metal catalysts as catalysts in organic reactions, in particular in olefin metathesis reactions.

This application is a divisional of U.S. patent application Ser. No.10/628,707 filed Jul. 28, 2003 now abandoned, entitled “Metathesiscatalysts”, the contents of which are hereby incorporated by referencein their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to polymeric transition metal catalysts, toprocesses for preparing them, to intermediates and also to the use ofthe transition metal catalysts as catalysts in organic reactions, inparticular in olefin metathesis reactions.

2. Brief Description of the Prior Art

Olefin metathesis reactions, for example ring-closing metathesis (RCM),cross-metathesis (CM) and ring-opening metathesis polymerizations(ROMP), are important synthetic methods for forming C—C bonds.

For olefin metathesis reactions, a multiplicity of catalyst systems hasbeen developed, which are described in summary, for example, in T. M.Trnka, R. H. Grubbs, Acc. Chem. Res. 2001, 34, 18-29.

With regard to activity, those catalyst systems which comprisealkoxybenzylidene complexes of transition metals in particular haveproven useful. However, the removal and, if possible, the reuse ofcatalysts is becoming more important, since catalyst metal residues inthe product may considerably impair its quality.

For example, Veldhuizen et al., J. Am. Chem. Soc. 2002, 124, 4954-4955disclose phosphine-alkoxybenzylidene complexes of ruthenium which aresuitable as reusable catalysts for the cross-metathesis of tricyclicnorbornenes. However, this restriction to specific substrates is ahindrance to industrial use.

Gessler et al., Tetrahedron Lett. 41, 2000, 9973-9976 also describestable ruthenium complexes which contain dihydroimidazol-2-ylidene andisopropoxybenzylidene ligands. However, the difficult recovery of thecatalyst is not satisfactory for industrial applications.

WO 02/14376 A2 describes dendrimeric ruthenium complexes which havedihydroimidazol-2-ylidene and isopropoxybenzylidene ligands and canadvantageously be removed from the reaction products in the catalyticreaction mixtures which result from olefin metathesis reactions.However, a disadvantage of these catalysts is the complicated synthesisof the dendritic framework.

There was therefore still a need for easily obtainable catalysts whichhave high activity even on reuse and can easily be removed from thecatalytic reaction mixtures.

SUMMARY OF THE INVENTION

Surprisingly, polymeric compounds have now been found which contain atleast

-   -   structural units of the formula (Ia),

-   -   where    -   M is a transition metal of the 8^(th) transition group of the        Periodic Table,    -   X¹ and X² are the same or different and are each chlorine,        bromine or iodine,    -   L is an N-heterocyclic carbene ligand of the formula (II)

-   -   -   where the direction of the arrow is intended to represent            the bond to M and where        -   B is a 1,2-ethanediyl or 1,2-ethenediyl radical which is            optionally mono- or disubstituted by C₁-C₄-alkyl,            C₆-C₁₅-arylalkyl or C₅-C₁₄-aryl and

    -   R⁶ and R⁷ are each independently C₁-C₂₀-alkyl or C₅-C₂₄-aryl,

    -   R¹ is cyclic, straight-chain or branched C₁-C₂₀-alkyl or        C₅-C₂₄-aryl and

    -   R², R³ and R⁴ are each independently hydrogen, C₁-C₂₀-alkyl,        C₅-C₂₄-aryl, halogen, C₁-C₄-fluoroalkyl, C₁-C₄-alkoxy,        C₅-C₁₄-aryloxy, (C₁-C₈-alkyl)OCO—, (C₁-C₈-alkyl)CO₂—,        (C₅-C₁₄-aryl)OCO— or (C₅-C₁₄-aryl)CO₂— and/or

    -   in each case two radicals in an ortho-arrangement to one another        from the group of R², R³ and R⁴ are part of a cyclic system        which consists of a carbon framework having 5 to 22 carbon        atoms, one or more carbon atoms of the cyclic system optionally        being replaced by heteroatoms from the group of sulphur, oxygen        or nitrogen, and the cyclic system also being optionally mono-        or polysubstituted by radicals selected from the group of        halogen, C₁-C₄-fluoroalkyl, (C₁-C₄-alkyl)OCO—,        (C₁-C₈-alkyl)CO₂—, (C₆-C₁₀-aryl)OCO— or (C₅-C₁₄-aryl)CO₂— and

    -   A is oxygen, sulphur, sulphoxyl, sulphonyl or CR⁸R⁹ where R⁸ and        R⁹ are each independently hydrogen or C₁-C₄-alkyl and

    -   D is C₁-C₈-alkylene, [(C₁-C₈-alkylene)-O—]_(n) where n=1 to 12,        (C₁-C₈-alkylene)CO₂—, (C₁-C₈-alkylene)-OCO—(C₁-C₈-alkylene),        (C₁-C₈-alkylene)CO₂—(C₁-C₈-alkylene), (C₁-C₈-alkylene)CONR¹⁰—,        (C₁-C₈-alkylene)NR¹⁰CO—, (C₁-C₈-alkylene)CONR¹⁰—(C₁-C₈-alkylene)        or (C₁-C₈-alkylene)NR¹⁰CO—(C₁-C₈-alkylene) where R¹⁰ is hydrogen        or C₁-C₄-alkyl

    -   and structural units of the formula (Ib)

-   where A, D, R¹, R², R³ and R⁴ each independently have the same    definitions and fulfil the same conditions as specified under the    formula (Ia) and    -   optionally structural units of the formula (Ic)

-   -   where    -   A has the same definition and fulfils the same conditions as        specified under formula (Ia) and    -   R¹¹ is C₁-C₈-alkyl, [(C₁-C₈-alkylene)-O—]_(n)—(C₁-C₈-alkyl)        where n=1 to 12, (C₁-C₈-alkylene)CO₂—(C₁-C₈-alkyl),        (C₁-C₈-alkylene)-OCO—(C₁-C₈-alkyl),        (C₁-C₈-alkylene)-OCO—(C₅-C₁₄-aryl),        (C₁-C₈-alkylene)CO₂—(C₅-C₁₄-aryl),        (C₁-C₈-alkylene)CONR¹⁰—(C₁-C₈-alkyl),        (C₁-C₈-alkylene)NR¹⁰CO—(C₁-C₈-alkyl),        (C₁-C₈-alkylene)CONR¹⁰—(C₅-C₁₄-aryl) or        (C₁-C₈-alkylene)NR¹⁰CO—(C₅-C₁₄-aryl) where R¹⁰ is hydrogen or        C₁-C₄-alkyl.

DETAILED DESCRIPTION OF THE INVENTION

Within the scope of the invention, all radical definitions andillustrations listed in general or within areas of preference may becombined with each other, i.e. the particular areas and areas ofpreference may also be combined as desired.

Wavy lines in formulae are intended to emphasize that in each case bothpossible isomers are intended to be encompassed by the representation.

For the purposes of the invention, alkyl, alkylene and alkoxy eachindependently represent a straight-chain, cyclic, branched or unbranchedalkyl, alkylene and alkoxy radical respectively, each of which mayoptionally be further substituted by C₁-C₄-alkoxy radicals. The sameapplies to the alkylene moiety of an arylalkyl radical.

In all contexts, C₁-C₄-alkyl is preferably, for example, methyl, ethyl,n-propyl, isopropyl, n-butyl and tert-butyl, C₁-C₈-alkyl is additionallyneopentyl, n-pentyl, cyclohexyl, n-hexyl, n-heptyl, n-octyl andisooctyl, and C₁-C₂₀-alkyl is further additionally, for example,n-decyl, n-dodecyl, n-hexadecyl and n-octadecyl.

In all contexts, C₁-C₄-alkylene is preferably, for example, methylene,1,1-ethylene, 1,2-ethylene, 1,1-propylene, 1,2-propylene, 1,3-propylene,1,1-butylene, 1,2-butylene, 2,3-butylene and 1,4-butylene, andC₁-C₈-alkylene is additionally 1,5-pentylene, 1,6-hexylene,1,1-cyclohexylene, 1,4-cyclohexylene, 1,2-cyclohexylene and1,8-octylene.

For the purposes of the invention, aryl is a carbocyclic radical orheteroaromatic radical in which no, one, two or three framework atomsper cycle, although at least one framework atom in the entire radical,is a heteroatom which is selected from the group of nitrogen, sulphurand oxygen. The carbocyclic aromatic radicals or heteroaromatic radicalsmay also be substituted by up to five identical or differentsubstituents per cycle, selected, for example, from the group ofhydroxyl, chlorine, fluorine, nitro and C₁-C₁₂-alkyl. For the purposesof the invention, aryl is preferably an above-defined carbocyclicradical.

The same applies to the aryl moiety of an arylalkyl radical.C₆-C₁₅-Arylalkyl is, for example, and with preference, benzyl.

For the purposes of the invention, fluoroalkyl is in each caseindependently a straight-chain, cyclic, branched or unbranched alkylradical which may be singly, multiply or fully substituted by fluorineatoms.

For example and with preference, C₁-C₄-fluoroalkyl is in all contextspreferably trifluoro-methyl, 2,2,2-trifluoroethyl, pentafluoroethyl andnonafluorobutyl.

The polymeric compounds containing at least the structural units of theformula (Ia) and (Ib) and optionally (Ic) may also contain structuralunits which are derived from olefins which are suitable for ring-openingmetathesis polymerization. These are sufficiently well known from theliterature (e.g. from T. M. Trnka, R. H. Grubbs, Acc. Chem. Res. 2001,34, 18-29 and the literature cited there).

Polymeric compounds containing structural units of the formulae (Ia) and(Ib) and optionally structural units of the formulae (Ic) are preferablythose which have a degree of polymerization (numerical average) of 6 to2000, particularly preferably 10 to 500.

It is pointed out that the scope of the invention also encompassespolymeric compounds in which the structural units of the formulae (Ia)and/or of the formulae (Ib) and/or optionally the structural units ofthe formulae (Ic) may in each case have different definitions for A andD or M, L, X¹, X² or R¹, R², R³, R⁴ or R¹¹, although preference is givento those polymeric compounds in which M, L, X¹ and X² in the structuralunits of the formula (Ia), and likewise R¹, R², R³ and R⁴ in thestructural units of the formula (Ia) and (Ib), and R¹¹ in any structuralunits of the formula (Ic) present and likewise A and D in the structuralunits of the formula (Ia) and (Ib) and any structural units of theformula (Ic) present are in each case identical.

Preference is further given to those polymeric compounds in which theproportion of the structural units of the formula (Ia) and of theformula (Ib) and any structural units of the formula (Ic) present(average proportion by weight) is 80% or more, preferably 90% or moreand particularly preferably 98% or more.

The ratio of structural units of the formula (Ia) to structural units ofthe formula (Ib) in the polymer is preferably 1:2 to 1:500, particularlypreferably 1:8 to 1:200.

When the polymeric compound also contains structural units of theformula (Ic), the ratio of structural units of the formula (Ia) tostructural units of the formula (Ic) is in addition preferably 10:1 to1:200, particularly preferably 1:1 to 1:100 and very particularlypreferably 1:10 to 1:50.

D in the structural units (Ia) and (Ib) is preferably bonded via theortho-position to the olefin or to the ylidene unit.

M in formula (Ia) is preferably ruthenium or osmium, particularlypreferably ruthenium.

X¹ and X² are preferably identical and are each chlorine or bromine,particularly preferably chlorine.

L in formula (Ia) is an N-heterocyclic carbene ligand of the formula(II).

B in formula (II) is preferably 1,2-ethanediyl or 1,2-ethenediyl.

R⁶ and R⁷ in formula (II) are preferably and in each case independently,although preferably identically, a primary C₅-C₂₀-alkyl radical, withthe proviso that the carbon atom bonded to the nitrogen atom bears atertiary alkyl radical, or are each a secondary C₃-C₂₀-alkyl radical, atertiary C₄-C₂₀-alkyl radical or a phenyl radical which is further mono-or polysubstituted, although at least in an ortho-position, byC₁-C₄-alkyl radicals.

R⁶ and R⁷ in the formula (III) are particularly preferably identical andare each isopropyl, sec-butyl, tert-butyl, 1-methylbutyl, 1-ethylpropyl,1,1-dimethylpropyl, 1,2-di-methylpropyl, 1-methylpentyl,1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 1-ethylbutyl,1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl,cyclopentyl, cyclohexyl, cycloheptyl, neopentyl, adamantyl, norbornyl,o-tolyl, 2,6-dimethylphenyl, 2-ethyl-6-methylphenyl,2,6-diisopropylphenyl, o-anisyl, 2,6-dimethoxyphenyl, mesityl andisityl.

-   R¹ is preferably a radical which is selected from the group of    ethyl, isopropyl, tert-butyl, neopentyl, cyclohexyl and cyclopentyl,    and even greater preference is given to isopropyl.-   R², R³ and R⁴ are preferably each independently hydrogen,    C₁-C₄-alkyl, fluorine, chlorine or C₁-C₄-fluoroalkyl, and are    particularly preferably identical and are each hydrogen.-   A is preferably oxygen or CH₂, and even greater preference is given    to oxygen.-   D is preferably [(C₁-C₄-alkylene)-O—]_(n) where n=1 or 2, or    (C₁-C₄-alkylene)CO₂—, particularly preferably (C₁-C₄-alkylene)-O—    and very particularly preferably CH₂O.-   R¹¹ is preferably (C₁-C₄-alkylene)-O—]_(n)—(C₁-C₄-alkyl) where n=1    or 2, (C₁-C₄-alkylene)CO₂—(C₁-C₄-alkyl) or    (C₁-C₄-alkylene)CO₂—(C₅-C₁₄-aryl), particularly preferably    CH₂O₂C—(C₁-C₄-alkyl) or CH₂OCO—(C₅-C₁₄-aryl), and very particularly    preferably CH₂OCOphenyl or CH₂OCO(o-methylaminophenyl), which may be    used as a fluorescence marker.

Very particularly preferably, the polymeric compounds according to theinvention contain structural units of the formula (Ia):

-   where R⁶ and R⁷ are identical and are each isopropyl, sec-butyl,    tert-butyl, 1-methylbutyl, 1-ethylpropyl, 1,1-dimethylpropyl,    1,2-dimethylpropyl, 1-methylpentyl, 1,1-dimethylbutyl,    1,2-dimethylbutyl, 1,3-dimethylbutyl, 1-ethylbutyl,    1,1,2-trimethyl-propyl, 1,2,2-trimethylpropyl,    1-ethyl-1-methylpropyl, cyclopentyl-, cyclohexyl-, cycloheptyl-,    neopentyl, adamantyl, norbornyl, o-tolyl, 2,6-dimethylphenyl,    2-ethyl-6-methylphenyl, 2,6-diisopropylphenyl, 2,6-dimethoxyphenyl    and mesityl.

Very particularly preferably, the polymeric compounds according to theinvention contain as structural units of the formula (Ib):

When the polymeric compounds according to the invention containstructural units of the formula (Ic), very particular preference isgiven to the following:

The polymeric compounds according to the invention containing structuralunits of the formulae (Ia) and (Ib) and optionally (Ic) are accessibleby a process which is likewise encompassed by the invention.

This is a process for preparing polymeric catalysts, which ischaracterized in that compounds of the formula (IIIa) and/or (IIIb)

where

-   R¹, L, X¹ and X² each have the definition and areas of preference    specified under formula (Ia) and-   ortho-arylene is an ortho-phenylene or ortho-naphthylene radical,    for example 1,2-naphthylene, and the radicals mentioned may also be    substituted by one, two, three or four radicals per cycle which are    selected from the group of C₁-C₄-alkyl, C₅-C₁₄-aryl and C₁-C₄-alkoxy    and-   Ar is C₅-C₁₄-aryl and-   R¹², R¹³ and R¹⁴ are each independently C₁-C₈-alkyl or C₅-C₁₄-aryl    are reacted    -   with at least one compound of the formula (IV)

-   -   where    -   R¹, R², R³, R⁴, A and D have the definition and areas of        preference specified under formula (Ia).    -   and optionally with at least one compound of the formula (V)

-   -   where    -   R¹¹ and A each have the definition and areas of preference        specified under formula (Ic)    -   and optionally with one or more further olefins which can be        polymerized by ring-opening metathesis.

The compounds of the formula (IV) are hitherto unknown and thereforelikewise encompassed by the invention.

In formula (IIIa), ortho-arylene is preferably ortho-phenylene.

In formula (IIIb), aryl is preferably phenyl.

Also, R¹², R¹³ and R¹⁴ in formula (IIIb) are preferably identical andeach C₁-C₈-alkyl or C₅-C₁₄-aryl, particularly preferably identical andeach cyclohexyl.

A particularly preferred compound of the formula (IV) is(7-oxa-2-norborn-2-en-5-yl-methyl) (2-isopropoxy-3-ethenylphenyl) ether(IVa).

The compounds of the formula (IIIa) and (IIIb) are known from theliterature or can be prepared in a similar manner to methods known fromthe literature (see in particular Veldhuizen et al., J. Am. Chem. Soc.2002, 124, 4954-4955).

The compounds of the formulae (IV) and (V) may be prepared in a similarmanner to the literature methods. As an example, the synthetic sequencefor the compound of the formula (IVa) is given.

Preference is given to carrying out the process according to theinvention in an organic solvent. Examples of useful organic solventsinclude amides, for example dimethylformamide, N-methylpyrrolidinone,halogenated aliphatic or optionally halogenated, aromatic solventshaving up to 16 carbon atoms, e.g. toluene, o-, m-, p-xylene,chloroform, dichloromethane, chlorobenzene, the isomericdichlorobenzenes, fluorobenzene, nitriles, e.g. acetonitrile andbenzonitrile, sulphoxides such as dimethyl sulphoxide or mixturesthereof.

Preferred organic solvents are toluene and dichloromethane.

The reaction temperature may be, for example −30° C. to 100° C.,preferably 10 to 40° C.

The reaction time may be, for example, 2 minutes to 24 hours, preferably5 min to 1 h.

When using compounds of the formula (IIIb), it is advantageous also touse compounds which are capable of scavenging phosphines. These arepreferably copper salts, in particular CuCl₂ and CuCl which are alsopreferably used in an equimolar amount or in a molar excess.

Depending on the choice of the molar ratios of the monomeric compounds(IIIa) and/or (IIIb), (IV) and any (V), a corresponding average molarcomposition is achieved in the polymeric compounds according to theinvention. The areas of preference specified above for the ratios of thestructural units of the formulae (Ia), (Ib) and any (Ic) consequentlyapply correspondingly to the preferred ranges of the ratios of monomericcompounds to be used.

The workup can be effected in such a way, for example, that anyinsoluble constituents present are filtered out and the filtrate isconcentrated, the residue is subsequently washed with organic solventand then optionally dried under reduced pressure.

In this way, the polymeric compounds according to the inventioncomprising the structural units of the formulae (Ia) and (Ib) and any(Ic) can be obtained in high yields. These polymeric compounds accordingto the invention are suitable, for example, as metathesis catalysts, inparticular for ring-closing metatheses, ring-opening metatheses,cross-metatheses and ring-opening metathesis polymerizations.

The invention therefore also encompasses a process for preparing olefinsby catalytic olefin metathesis, which is characterized in that thecatalysts used are the polymeric compounds according to the inventioncontaining the structural units of the formulae (Ia) and (Ib) andoptionally (Ic).

An example of a possible procedure is to react the reactant olefin,optionally in an organic solvent, with the polymeric compounds accordingto the invention and in this way to obtain catalytic reaction mixtureswhich contain the product.

The reaction temperature may be, for example, −30 to 100° C.

In a preferred embodiment, the polymeric compounds according to theinvention are removed from the catalytic reaction mixtures and reusedfor the preparation of olefins by catalytic olefin metathesis. Theprocedures of removal and reuse can be repeated once or more than once.

In a further preferred embodiment of the process according to theinvention, the removal can be effected in such a way that sufficientaliphatic hydrocarbons, preferably having 5 to 12 carbon atoms, and/ordiethyl ether are added to the catalytic reaction mixtures to at leastpartially precipitate out the polymeric compounds. Subsequently, thepolymeric compounds according to the invention can be removed byfiltration and/or decanting from the product solution.

Aliphatic hydrocarbons having 5 to 12 carbon atoms are, for example andwith preference, n-pentane and n-hexane.

The polymeric compounds according to the invention are suitable inparticular as catalysts, preferably as catalysts in metathesisreactions, for example cross-metatheses, ring-closing metatheses andring-opening metathesis polymerizations, optionally with subsequentcross-metathesis.

They are notable for their high activities for a multiplicity ofdifferent substrates, for example ring-closing metatheses at lowcatalyst loading result in quantitative conversions even in a short timeand at low temperatures.

The polymeric compounds according to the invention can also be removedeasily and in high yields from the catalytic reaction mixtures and onlyhave a small loss of activity on reuse.

EXAMPLES Example 1 Preparation of methyl 7-oxanorborn-2-en-5-ylcarbonate

Furan and methyl acrylate were distilled before use.

A mixture of furan (22.6 ml, 311 mmol) and methyl acrylate (20.0 ml, 222mmol) was cooled to −20° C. under nitrogen. AlCl₃ (8.880 g, 67 mmol) wasadded to this mixture in four portions, likewise under nitrogen. Thereaction mixture was stirred for 30 min and subsequently allowed to heatto room temperature within 2 h. The crude reaction mixture was admixedwith ethyl acetate (30 ml) and filtered. The filtrate was washed withsaturated NH₄Cl solution (50 ml) and dried over magnesium sulphate andconcentrated under reduced pressure.

The crude product was purified by flash chromatography (using 50:50cyclohexane:ethyl acetate as the eluent) to obtain the pure product 16.2g (55% of theory) as a 55:45 mixture of the exo- and endo-isomers.

δ_(H) (200 MHz, CDCl₃, E1=exo-isomer, E2=endo-isomer): 6.40-6.46 (1H, m,H-5 E2), 6.32-6.40 (2H, m, H-5, 6 E1), 6.22 (1H, dd, J 2, 15 Hz, H-6E2), 5.12-5.20 (2H, m, H-1, 4 E2), 4.98-5.08 (2H, m, H-1, 4 E1), 3.72(3H, s, CH₃ E1), 3.62 (3H, s, CH₃ E2), 3.10 (1H, quint., J 6 Hz, H-3E1), 2.42 (1H, dd, J 3, 8 Hz, H-3 E1), 2.04-2.22 (1H, m, H-2 E1),1.48-1.70 (2H, m, H-3 E2), 1.20-1.30 (1H, t, 6 Hz, H-2 E2).

Example 2 Preparation of 7-oxanorborn-2-en-5-ylmethanol

A solution of methyl 7-oxanorborn-2-en-5-ylcarbonate (16.163 g, 105mmol, see Example 1) in THF (75 ml) was added dropwise with stirring andunder nitrogen to a suspension of lithium aluminium hydride (4.376 g,115 mmol) in anhydrous THF (100 ml), in such a way that the solutionboiled gently. The reaction mixture was subsequently stirred at roomtemperature for another 12 h and then quenched by cautiously adding anice-water mixture. The organic phase was removed and the aqueous phaseextracted with ethyl acetate (3×200 ml). The combined organic phaseswere washed with water (600 ml) and saturated sodium chloride solution(600 ml), dried over sodium sulphate and concentrated under reducedpressure.

The crude product was purified by flash chromatography (using a 50:50mixture of cyclohexane and ethyl acetate). 3.7 g (32% of theory) of thepure product were obtained.

δ_(H) (500 MHz, CDCl₃, E1=exo-isomer, E2=endo-isomer): 6.38 (1H, dd, J1.5, 5.9 Hz, H-5 E2), 6.32 (2H, br s, H-5, 6 E1), 6.28 (1H, dd, J 1.0,5.9 Hz, H-6 E2), 5.01 (1H, d, J 3.7 Hz, H-1 E2), 4.93 (2H, m, H-1, 4E1), 4.87 (1H, s, H-4 E2), 3.75 (1H, dd, J 5.1, 10.4 Hz, HCHOH E2),3.52-3.59 (2H, m, CH ₂OH E1), 3.19 (1H, t, J 10.1 Hz, HCHOH E2), 2.44(1H, m, H-2 E2), 1.97-2.00 (1H, m, H-3 E2), 1.76-1.81 (1H, m, H-2 E1),1.34-1.39 (2H, m, H-3 E1), 0.70 (1H, dd, J 4.1, 11.3 Hz, H-3 E2).

Example 3 Preparation of 7-oxanorborn-2-en-5-yl-methyl bromide

Tetrabromomethane (1.161 g, 3.50 mmol) was added to a solution of7-oxanorborn-2-en-5-ylmethanol (0.305 g, 2.50 mmol, from Example 2) inCH₂Cl₂ (12.5 ml). The solution was cooled to 0° C. and admixed withtriphenylphosphine (1.836 g, 7 mmol). The reaction mixture was allowedto warm to room temperature and stirred for 12 h. The solvent wasremoved under reduced pressure and the remaining solid was taken up incyclohexane. The crude product was purified by flash chromatography(using a 98:2 mixture of cyclohexane and ethyl acetate). 0.3 g (59% oftheory) of the pure product were obtained. The product was stored undercool conditions with the exclusion of light.

δ_(H) (200 MHz, CDCl₃, E1=exo-isomer, E2=endo-isomer): 6.46 (1H, dd, J2, 6 Hz, H-5 E2), 6.35 (2H, br s, H-5, 6 E1), 6.36 (1H, dd, J 2, 8 Hz,H-6 E2), 4.96-5.08 (2H, m, H-1, 4 E2), 4.99 (1H, d, J 4 Hz, H-1 E1),4.86 (1H, s, H-4 E1), 3.42-3.49 (2H, m, CH ₂Br E1), 3.36 (1H, dd, J 7,10 Hz, HCHBr E2), 3.19 (1H, t, J 10 Hz, HCHBr E2), 2.58-2.68 (1H, m, H-2E2), 2.06-2.12 (1H, m, H-3 E2), 2.00-2.06 (1H, m, H-2 E1), 1.37-1.43(1H, m, H-3 E1), 1.36 (1H, dt, J 4, 12 Hz, H-3 E1), 0.80 (1H, dd, J 4,12Hz, H-3 E2).

Example 4 Preparation of 2-hydroxy-3-acetoxybenzaldehyde

A solution of 2,3-dihydroxybenzaldehyde (4.000 g, 28.96 mmol) and aceticanhydride (3.260 g, 32.00 mmol) in acetic acid (40 ml) was heated toreflux under a nitrogen atmosphere for 72 h.

After cooling, the reaction mixture was poured into ice-water, and awhite solid precipitated out.

After extraction with CH₂Cl₂ (2×100 ml), the combined organic phaseswere rapidly washed with ice-cold water (2×100 ml) and saturated sodiumchloride solution (100 ml). After drying over magnesium sulphate andconcentrating to a volume of approx. 70 ml, hexane (50 ml) was added andthe mixture was concentrated again under reduced pressure until thecommencement of crystallization. The mixture was aerated and cooled to0° C. After one hour at 0° C., the precipitated solid was filtered offwith suction and dried under high vacuum.

3.95 g (76% of theory) of 2-hydroxy-3-acetoxybenzaldehyde were obtainedas a colourless crystalline solid.

δ_(H) (500 MHz, CDCl₃): 11.12 (1H, s, CHO), 9.92 (1H, s, OH), 7.49 (1H,dd, J 1.5, 7.7 Hz), 7.32 (1H, dd, J 0.7, 7.9 Hz), 7.03 (1H, dd, J 7.7,7.9 Hz), 2.86 (3H, s, OCOMe).

Example 5 Preparation of 2-isopropoxy-3-hydroxybenzaldehyde

A 100 ml round-bottomed flask was charged with dried molecular sieve 4 Amol (approx. 1 g) and dried (130° C., 12 h) K₂CO₃ (5.520 g, 40.00 mmol)and charged under a nitrogen atmosphere with a solution of2-hydroxy-3-acetoxybenzaldehyde (3.600 g, 19.98 mmol, from Example 3) indried DMF (50 ml). After stirring for 30 minutes, 2-bromopropane (13.00ml, 138.88 mmol) was added via a cannula and the resulting yellowsolution was heated to 50° C. for 12 h. After cooling to roomtemperature, water (100 ml) was added. The biphasic mixture wasextracted with diethyl ether (3×200 ml). The combined organic phaseswere washed with water (5×100 ml), dried over magnesium sulphate andconcentrated under reduced pressure.

¹H NMR analysis showed a 92:8 mixture of mono- and bis-alkylatedproducts. To hydrolyse the 3-acetoxy group, the residue was taken up inmethanol (20 ml) and admixed with a 30% solution of sodium methoxide inmethanol until the resulting yellow solution gained no more colourintensity on further addition.

The methanolic solution was concentrated under reduced pressure todryness and the remaining residue was taken up in water (40 ml). Theyellow solution of the phenoxide was extracted with MTBE (2×20 ml), inorder to remove the undesired bis-alkylated by-product. Subsequently,acetic acid was added to the aqueous phase until decolorization.

Subsequently, extraction was effected using MTBE (5×50 ml), and thecombined organic phases were dried over magnesium sulphate andconcentrated under reduced pressure.

The yellow residue was purified by column chromatography (eluentCH₂Cl₂). 2.66 g (74% of theory) of the product were obtained as acolourless solid.

δ_(H) (500 MHz, CDCl₃): 10.25 (1H, s, CHO), 7.37 (1H, dd, J 1.4, 7.7Hz), 7.20 (1H, dd, J 1.4, 7.9 Hz), 7.11 (1H, dd, 7.7, 7.9 Hz), 5.96 (1H,s, OH), 4.33 (1H, septet, J 6.1 Hz CH(CH₃)₂), 1.38 (6H, d, J 6.1 Hz,CH(CH ₃)₂).

Example 6 Preparation of 7-oxa-2-norborn-2-en-5-ylmethyl2-isopropoxy-3-formylphenyl ether

7-Oxanorborn-2-en-5-ylmethyl bromide (1.0 g, 5.3 mmol from Example 3)and potassium carbonate (0.498 g, 3.6 mmol) were added to a solution of2-isopropoxy-3-hydroxybenzaldehyde (0.317 g, 1.8 mmol from Example 5) indry DMF (6 ml) and the reaction mixture was stirred at 50 to 60° C. for12 h. After cooling to room temperature, water (10 ml) was added. Theresulting biphasic mixture was extracted with MTBE (3×20 ml). Thecombined organic phases were washed with water (5×30 ml) and sodiumhydrogencarbonate solution (30 ml), dried over magnesium sulphate andconcentrated under reduced pressure. The crude product was purified byflash chromatography (eluent CH₂Cl₂). 0.4 g (76% of theory) of the pureproduct was obtained.

δ_(H) (500 MHz, CDCl₃, E1=exo-isomer, E2=endo-isomer): 10.45 (1H, s,CHO), 7.42 (1H, dd, J 1.9, 7.5 Hz, ArH), 7.02-7.14 (2H, m, ArH), 6.45(1H, dd, J 1.6, 5.9 Hz, H-6 E2), 6.38 (2H, ddd, J 1.5, 5.9, 13.1 Hz,H-5, 6 E1), 6.31 (1H, dd, J 1.3, 5.8 Hz, H-5 E2), 5.13 (2H, d, J 4.2 Hz,H-1 E2), 5.01 (2H, d, J 3.3 Hz, H-4 E2), 4.96-5.01 (2H, m, H-4, 1 E1),4.62-4.68 (1H, m, CH(CH₃)₂), 4.00-4.04 (2H, m, CH ₂O E1), 3.93 (1H, dd,J 6.4, 9.1 Hz, HCHO E2), 3.54 (1H, t, J 9.1 Hz, HCHO E2), 2.76-2.81 (1H,m, H-2 E2), 2.10-2.15 (2H, m, H-3 E1 & E2), 1.51-1.54 (1H, m, H-3 E1),1.56 (1H, dd, J 8, 12 Hz, H-2 E1), 1.36 (6H, d, J 6.1 Hz, CH(CH₃)₂),0.86 (1H, dd, J 4.1, 11.4 Hz, H-3 E2).

Example 7 Preparation of 7-oxa-2-norborn-2-en-5-ylmethyl2-isopropoxy-3-ethenylphenyl ether

Potassium tert-butoxide (0.218 g, 1.94 mmol) was added at 0° C. in oneportion to a suspension of methyltriphenylphosphonium bromide (0.694 g,1.94 mmol) in dry diethyl ether (5 ml) and the reaction mixture wasstirred for 10 min. Subsequently, a solution of7-oxa-2-norborn-2-en-5-ylmethyl 2-isopropoxy-3-formylphenyl ether (0.280g, 0.97 mmol from Example 6) in diethyl ether (3.6 ml) was added and themixture was stirred at 0° C. for a further 20 min. Afterwards, themixture was quenched by adding saturated ammonium chloride solution. Theaqueous phase was extracted using diethyl ether (3×10 ml) and, afterwashing with water (30 ml) and saturated sodium chloride solution (30ml), the combined organic phases were dried over magnesium sulphate andconcentrated under reduced pressure.

The crude product was purified by flash chromatography (eluent CH₂Cl₂).0.22 g (79% of theory) of the pure product was obtained.

δ_(H) (500 MHz, CDCl₃, E1=exo-isomer, E2=endo-isomer): 7.09-7.15 (2H, m,ArH), 6.95-6.97 (1H, m, ArH), 6.73 (1H, d, J 8.0 Hz, ArCH), 6.43 (1H,dd, J 1.3, 5.8 Hz, H-6 E2), 6.36 (2H, s, H-5, 6 E1), 6.27 (1H, dd, J0.8, 5.8 Hz, H-5 E2), 5.71 (1H, d, J 17.8 Hz, HCH═CH), 5.26 (1H, dd, J0.9, 11.1 Hz, HCH═CH), 5.15 (1H, d, J 3.7 Hz, H-1 E2), 4.97-4.99 (3H, m,H-4 E2 & H-4, 1 E1), 4.45 (1H, septet, J 6.1 Hz, CH(CH₃)₂), 3.94-4.02(2H, m, CH ₂O E1), 3.91 (1H, dd, J 6.1, 9.1 Hz, HCHO E2), 3.49 (1H, t, J9.1 Hz, HCHO E2), 2.75-2.81 (1H, m, H-2 E2), 2.08-2.13 (2H, m, H-3 E1 &E2), 1.50 (1H, dd, J 8.1, 11.5 Hz, H-3 E1), 1.56 (1H, dt, J 11.5, 3.9Hz, H-2 E1), 1.32 (6H, d, J 6.1 Hz, CH(CH ₃)₂), 0.84 (1H, dd, J 4.1,11.4 Hz, H-3 E2).

Example 8 Preparation of 7-oxa-2-norborn-2-en-5-yl-methyl benzoate

A solution of benzoyl chloride (0.93 ml, 8 mmol) in CH₂Cl₂ (8 ml) wasadded dropwise at 0° C. to a mixture of 7-oxanorborn-2-en-5-ylmethanol(0.505 g, 4.0 mmol from Example 2), 4-dimethylaminopyridine (0.049 g,0.4 mmol) and triethylamine (2.2 ml, 16 mmol) in CH₂Cl₂ (8 ml). Thereaction mixture was stirred at room temperature and the progress of thereaction was followed by thin-layer chromatography (eluent 80:20 ethylacetate:cyclohexane). After 2.5 h, the reaction mixture was quenched byadding water (20 ml). The product was extracted using CH₂Cl₂ (3×20 ml).The combined organic phases were washed with dilute hydrochloric acid,10% NaHCO₃-solution (60 ml), water (60 ml) and concentrated sodiumchloride solution (60 ml), dried over magnesium sulphate andconcentrated under reduced pressure.

The crude product was purified by flash chromatography (eluent 70:30 to90:10 CH₂Cl₂:cyclohexane). 0.68 g (74% of theory) of the pure productwas obtained.

δ_(H) (500 MHz, CDCl₃, E1=exo-isomer, E2=endo-isomer): 8.03-8.07 (2H, m,ArH), 7.55-7.57 (1H, m, ArH), 7.43-7.47 (2H, m, ArH), 6.41 (1H, dd, J1.4, 5.8 Hz, H-5 E2), 6.33-6.36 (3H, m, H-5, 6 E1 & H-6 E2), 5.06 (2H,d, J 3.7 Hz, H-1 E2), 4.98-5.01 (2H, m, H-1, 4 E1), 4.92 (1H, s, H-4E2), 4.48 (1H, dd, J 6.0, 10.8 Hz, HCHO E1), 4.27 (1H, dd, J 6.2, 11.1Hz, HCHO E2), 3.87 (1H, t, J 10.8 Hz, HCHO E1), 3.87 (1H, t, J 11.1 Hz,HCHO E2) 2.66-2.71 (1H, m, H-2 E2), 2.03-2.14 (2H, m, H-3 E2 & H-2 E1),1.48 (1H, dd, J 7.9, 11.5Hz, H-3 E1), 1.41 (1H, dt, J 4.0, 8.0Hz, H-3E1), 0.87 (1H, dd, J 4.1, 11.3 Hz, H-3 E2).

Example 9 Preparation of a Polymeric Catalyst

A solution of dichlorobenzylidene-(N,N-bismesitylimidazolinylidene)tricyclohexylphosphine-ruthenium (II) (7.4 mg, 0.0087 mmol) in CH₂Cl₂ (2ml) was added via a cannula to a solution of7-oxa-2-norborn-2-en-5-ylmethyl 2-isopropoxy-3-ethenylphenyl ether (25mg, 0.087 mmol from Example 7) and 7-oxa-2-norborn-2-en-5-ylmethylbenzoate (60 mg, 0.261 mmol from Example 8) in CH₂Cl₂ (3 ml) in a 5 mlround-bottomed flask under a nitrogen atmosphere and with vigorousstirring. After 10 min, the ¹H NMR analysis of the red reaction solutionshowed the complete conversion of the reactants, recognizable by thedisappearance of the olefinic norbornene signals at 6.2-6.5 ppm. Afteradding CuCl (1 mg, 0.101 mmol), the resulting solution was heated toreflux for one hour, resulting in a pale green solution.

After cooling, the reaction solution was concentrated under reducedpressure to dryness and the residue was taken up in a 1:1 mixture ofhexane and CH₂Cl₂. The insoluble copper salts were removed by filtrationthrough a Pasteur pipette filled with cotton wool.

The clear, green solution was concentrated to dryness under reducedpressure and the solid residue was washed successively with hexane (10ml) and diethyl ether (10 ml). After drying under high vacuum, thepolymeric product (74.5 mg, 93% of theory) was obtained as a pale green,adhesive solid. The catalyst loading of the polymeric product can bedetermined by integration of the ¹H NMR signals at 16.67 and 7.99 ppm.

δ_(H) (500 MHz, CDCl₃): 16.67 (1H, bs, Ru═CH, 7.99 (60H, bs, o-Arester), 7.50 (31H, bs), 7.38 (62H, bs), 7.04 (18H, bs), 6.91 (9H bs),6.74 (9H, bs), 5.7-5.6 (90H, bs) 5.21 (10H, bs), 4.7-3.7 (180H, m), 2.78(20H, bs), 2.37 (61H, bs), 2.01 (50H, bs) 1.23 (60H, bs);

N.B.: the overlapping and very broad signals cause some integrals of thehigh-field signals to become closer together, but neverthelessconsistent for different polymer charges.

Examples 10-24 General Procedure for Carrying Out Metathesis CatalysisUsing the Polymeric Catalyst from Example 9

The substrate (compounds 14 to 21) (0.12 mmol) CH₂Cl₂ (1.6 ml) was addedat room temperature to a solution of the polymeric catalyst from Example9 (1.2×10⁻³ mmol) in CH₂Cl₂ (1 ml) under a nitrogen atmosphere. Theresulting pale green solution was stirred until the substrate had beenquantitatively converted according to the ¹H NMR spectrum or thin-layerchromatography. After the reaction, the catalyst can be removed as agreen adhesive material from the catalytic reaction mixture by addingcold diethyl ether (7 ml). Alternatively, the addition of cold hexane ora diethyl ether-hexane mixture leads to the precipitation of thecatalyst as a green solid. The products (compounds 22 to 29) couldsubsequently be obtained by filtering and removing the solvent.

The catalysis results are compiled in Tables 1 and 2.

TABLE 1 Activity of the polymeric catalyst from Example 9 in metathesisreactions. Example Substrate Product/(reaction time) Conversion (%) 10

>98 11

>98 12

>98 13

>98 14

>98 15

>98 16

>98 17

>98

TABLE 2 Recyclability of the polymeric catalyst from Example 9 in thering-closing metathesis of toluenesulphonyl-N,N-diallylamide ExampleCycle Time (min) Conversion (%) 18 1 60 >98 19 2 60 >98 20 3 60 >98 21 460 >98 22 5 60 >98 23 6 120 >98 24 7 240 >98

1. Process for preparing polymeric compounds, characterized in thatcompounds of the formula (IIIa) and/or (IIIb)

where R¹ is cyclic, straight-chain or branched C₁-C₂₀-alkyl orC₅-C₂₄-aryl; L is an N-heterocyclic carbene ligand of the formula (II)

where the direction of the arrow is intended to represent carbeneelectrons and the bond to M and where B is 1,2-ethanediyl or1,2-ethenediyl radical which is optionally mono- or disubstituted byC₁-C₄-alkyl, C₆-C₁₅-arylalkyl, or C₅-C₁₄-aryl; and X¹ and X² are thesame or different and are each chlorine, bromine or iodine, andortho-arylene is an ortho-phenylene or ortho-naphthylene radical andsaid radicals may also be substituted by one, two, three or fourradicals per cycle which are selected from the group of C₁-C₄-alkyl,C₅-C₁₄-aryl and C₁-C₄-alkoxy and Ar is C₅-C₁₄-aryl and R¹², R¹³ and R¹⁴are each independently C₁-C₈-alkyl or C₅-C₁₄-aryl are reacted with atleast one compound of the formula (IV)

where R¹ is defined above with respect to formula (IIIa) and/or formula(IIIb); R², R³ and R⁴ are each independently hydrogen, C₁-C₂₀-alkyl,C₅-C₂₄-aryl, halogen, C₁-C₄-fluoroalkyl, C₁-C₄-alkoxy, C₅-C₁₄-aryloxy,(C₁-C₈-alkyl)OCO—, (C₁-C₈-alkyl)CO₂—, (C₅-C₁₄-aryl)OCO— or(C₅-C₁₄-aryl)CO₂— and/or in each case two radicals in anortho-arrangement to one another from the group of R², R³ and R⁴ arepart of a cyclic system which consists of a carbon framework having 5 to22 carbon atoms, one or more carbon atoms of the cyclic systemoptionally being replaced by heteroatoms from the group of sulphur,oxygen or nitrogen, and the cyclic system also being optionally mono- orpolysubstituted by radicals selected from the group of halogen,C₁-C₄-fluoroalkyl, (C₁-C₄-alkyl)OCO—, (C₁-C₈-alkyl)CO₂—,(C₆-C₁₀-aryl)OCO— or (C₅-C₁₄-aryl)CO₂—; A is oxygen, sulphur, sulphoxyl,sulphonyl or CR⁸R⁹ where R⁸ and R⁹ are each independently hydrogen orC₁-C₄-alkyl and D is C₁-C₈-alkylene, [(C₁-C₈-alkylene)-O—]_(n) where n=1to 12, (C₁-C₈-alkylene)CO₂—, (C₁-C₈-alkylene)-OCO—(C₁-C₈-alkylene),(C₁-C₈-alkylene)CO₂—(C₁-C₈-alkylene), (C₁-C₈-alkylene)CONR¹⁰—,(C₁-C₈-alkylene)NR¹⁰CO—, (C₁-C₈-alkylene)CONR¹⁰—(C₁-C₈-alkylene) or(C₁-C₈-alkylene)NR¹⁰CO—(C₁-C₈-alkylene) where R¹⁰ is hydrogen orC₁-C₄-alkyl.
 2. Process according to claim 1, characterized in that thereaction is also effected with at least one compound of the formula (V),

where A has the same definition and fulfils the same conditions asspecified under the formula (IV) in claim 1; and R¹¹ is C₁-C₈-alkyl,[(C₁-C₈-alkylene)-O—]_(n)—(C₁-C₈-alkyl) where n=1 to 12,(C₁-C₈-alkylene)CO₂—(C₁-C₈-alkyl), (C₁-C₈-alkylene)-OCO—(C₁-C₈-alkyl),(C₁-C₈-alkylene)-OCO—(C₅-C₁₄-aryl), (C₁-C₈-alkylene)CO₂—(C₅-C₁₄-aryl),(C₁-C₈-alkylene)CONR¹⁰—(C₁-C₈-alkyl),(C₁-C₈-alkylene)NR¹⁰CO—(C₁-C₈-alkyl),(C₁-C₈-alkylene)CONR¹⁰—(C₅-C₁₄-aryl) or(C₁-C₈-alkylene)NR¹⁰CO—(C₅-C₁₄-aryl) where R¹⁰ is hydrogen orC₁-C₄-alkyl.
 3. Process according to claim 1, wherein the reaction isalso effected with one or more further olefins which can be polymerizedby ring-opening metathesis.
 4. Process according to claim 1, whereincompound of formula (IV) is 7-Oxa-2-norborn-2-en-5-ylmethyl2-isopropoxy-3-ethenylphenyl ether.
 5. Process for preparing olefins bycatalytic olefin metathesis comprising providing as catalysts to themetathesis reaction polymeric compounds, wherein said polymericcompounds are prepared by providing compounds of the formula (IIIa)and/or (IIIb)

where R¹ is cyclic, straight-chain or branched C₁-C₂₀-alkyl orC₅-C₂₄-aryl; L is an N-heterocyclic carbene ligand of the formula (II)

where the direction of the arrow is intended to represent carbeneelectrons and the bond to M and where B is 1,2-ethanediyl or1,2-ethenediyl radical which is optionally mono- or disubstituted byC₁-C₄alkyl, C₆-C₁₅-arylalkyl, C₅-C₁₄-aryl; and X¹ and X² are the same ordifferent and are each chlorine, bromine or iodine, and ortho-arylene isan ortho-phenylene or ortho-naphthylene radical and said radicals mayalso be substituted by one, two, three or four radicals per cycle whichare selected from the group of C₁-C₄-alkyl, C₅-C₁₄-aryl and C₁-C₄-alkoxyand Ar is C₅-C₁₄-aryl and R¹², R¹³ and R¹⁴ are each independentlyC₁-C₈-alkyl or C₅-C₁₄-aryl and reacting compounds of formula (IIIa) and(IIIb) with at least one compound of the formula (IV)

where R¹ is defined above with respect to formula (IIIa) and/or formula(IIIb); R², R³ and R⁴ are each independently hydrogen, C₁-C₂₀-alkyl,C₅-C₂₄-aryl, halogen, C₁-C₄-fluoroalkyl, C₁-C₄-alkoxy, C₅-C₁₄-aryloxy,(C₁-C₈-alkyl)OCO—, (C₁-C₈-alkyl)CO₂—, (C₅-C₁₄-aryl)OCO— or(C₅-C₁₄-aryl)CO₂— and/or in each case two radicals in anortho-arrangement to one another from the group of R², R³ and R⁴ arepart of a cyclic system which consists of a carbon framework having 5 to22 carbon atoms, one or more carbon atoms of the cyclic systemoptionally being replaced by heteroatoms from the group of sulphur,oxygen or nitrogen, and the cyclic system also being optionally mono- orpolysubstituted by radicals selected from the group of halogen,C₁-C₄-fluoroalkyl, (C₁-C₄-alkyl)OCO—, (C₁-C₈-alkyl)CO₂—,(C₆-C₁₀aryl)OCO— or (C₅-C₁₄-aryl)CO₂—; A is oxygen, sulphur, sulphoxyl,sulphonyl or CR⁸R⁹ where R⁸ and R⁹ are each independently hydrogen orC₁-C₄-alkyl and D is C₁-C₈-alkylene, [(C₁-C₈-alkylene)-O—]_(n) where n=1to 12, (C₁-C₈-alkylene)CO₂—, (C₁-C₈-alkylene)-OCO—(C₁-C₈-alkylene),(C₁-C₈-alkylene)CO₂—(C₁-C₈-alkylene), (C₁-C₈-alkylene)CONR¹⁰—,(C₁-C₈-alkylene)NR¹⁰CO—, (C₁-C₈-alkylene)CONR¹⁰—(C₁-C₈-alkylene) or(C₁-C₈-alkylene)NR¹⁰CO—(C₁-C₈-alkylene) where R¹⁰ is hydrogen orC₁-C₄-alkyl.
 6. Process according to claim 5, wherein the catalysts areremoved from the catalytic reaction mixtures and reused for thepreparation of olefins by catalytic olefin metathesis.